Some 3d printing stuff

I've been messing around with 3d printers for a while and tried a lot of the options for machines and support systems over the years. I was having a tidy up to sort out the mess on my workbench and found one of the old raspberry pi astroprint units I'd used with one of the older 3d printers I had which I replaced with the excellent Prusa i3Mk2.

Astroprint is a cloud based slicer and printer controller that uses a local raspberry pi to control the machine allowing you to drag drop models onto a webpage and have the machine go print the thing without needing to swap sd cards around. At the time this was pretty amazing as none of the machines had wifi natively (these days that is an option on more expensive printers) it had some issues though with it being proprietary and requiring internet it's slicer was also only so so and it also tended to lose the printer connection requiring resets which defeated the point of the thing.

I thought about rejigging that to run the prusa but I remembered at the time I got the astroprint unit there was an opensource alternative called Octoprint which was in its infancy and less well featured but since time had passed I thought I should see if it had gotten to the point of being useful.

Octoprint like astroprint has a raspberry pi image (called Octopi) which you deploy to a pi (it supports most of them but rpi 3 and 4 are the recommended versions) the you connct to the printer via usb and the pi connects to the network. Unlike astroprint it's basically self contained it serves a local webserver you can access to control your printer remotely (for moving the print nozzle around or preheating the nozzle or bed or changing filament or some such) and drag and drop files to print. It doesn't do the slicing aspect which is fine being able to use better slicers like simplify 3d, cura, or prusaslicer gives more control over the slicing process which is preferable. You just slice your models in your prefered slicer export the gcode drag and drop onto the webpage hit print away it goes.

You can then monitor the process with various modes like temperature gcode simulation or if you attach a camera live streaming video of the print in process.

It also supports a time lapse mode which is ok it try to synchronize the layer change with when it snaps the image but because the y axis of the printer moves the print bed itself the print is often in a different position when the shot is taken making it jump around. This is fine but if you can make the model static in the frame and synchronise the capture with the layer movement you get those nice videos of the objects just appearing out of thin air one layer at a time. With the native mode the best you can hope for is something like this where mostly the object stays static although sometimes you get it jumping around depending on where the y axis stops at the end of a layer. You also get the print head in the way some of the time.

For more elaborate prints it will be moving all over the place. One option is to affix the camera to the build plate so it moves with the print but that has other issues where the background will move around it also might be difficult to attach it without fouling the y axis or reducing your print volume and extra mass on your y axis might lead to print artifacts.

Luckily there is a solution, octoprint supports plugins and one of these is called Octolapse which uses the control of the print afforded by Octoprint to both synchronize the images to the layer transition but also reposition the print bed and the print nozzle for the consistent shot. Here is one of the tests I did with this plugin enabled.

As you can see a vast improvement, the print seems to magically form from the bed up and while I need to reposition the camera a little to get the thing framed better it's a good first step into getting fun timelapse videos out of the printer showing objects magically form one layer at a time.

So Octoprint is a worthy addition to any 3d printing setup (at least any FDM machine it unfortunately doesn't support SLA printers) adding some great additional features to any setup.